Optimizing your site is as easy as A/Bby Steve Lionais
A/B testing is simply comparing one page design (A) against another page design (B) on your web site. Below are the steps to conduct an A/B test.

1. Identify metrics, what is success to you?
   Typically this is the conversion rate of the page but it can be any relevant metric such as the average visit duration, number of items in a shopping cart, or average order value.
2. Choose an element on the page to change
   This could include a ‘Contact Us’ form, submit button, text, the headline, images, or colours. However, only choose one element to test in each series.
3. Change one element in each new page
   Create a number of pages with only one change on each page. Change only one element for each test series. On a Contact Us page,  try changing the number of fields in the form, the layout of the form, the size of the boxes, or pre-populating data, and even the style and size of the submit button.
4. Deploy the test pages
   Launch the pages and direct traffic from the site randomly to each test page. You’ll need some help from your IT department here to ensure that the user experience isn’t affected and you get a statistically relevant sample on each test page.
5. Measure the results
   Using your web analytics software measure which variation had the highest conversion rate. This is the winning element.
6. Repeat with different elements
   Now, you want to repeat the process with different page elements. Eventually you’ll build a highly optimized page.
   

I bet you’re thinking, isn't this is a lot of work?  Well, it is. That’s why there’s commercial testing solutions that automate much of this process. My favorite is Google Website Optimizer because it offers a robust solution, and it’s free to Google Analytics users. Other paid solutions include Test & Target from Omniture and Personalization from Sitebrand.

These solutions use both multivariate testing and A/B testing methods as well as handling the random page serving process. The multivariate testing method allows you to test multiple page elements at once to figure out which combination is the most effective.

Testing important pages on your web site can have a significant impact on profitability without spending any marketing dollars. Be sure to consider it in your product planning & design strategy.